Effect of treatment of arterial hypertension on renal function in patients with imminent and overt diabetic nephropathy

: The effect was studied of blood pressure lowering treatment on renal failure and albuminuria (UAE) in patients with type I diabetes (IDDM) and imminent nephropathy as well as in patients with over diabetic nephropathy. The group of 24 patients with imminent nephropathy was subdivided: 1. twelve patients with borderline or overt hypertension with mean BP lowered not below 100 mmHg, and 2. twelve patients with BP within the normal limits, taking no hypotensive agents. In the other group of 12 patients with overt diabetic nephropathy hypertension was lowered below 105 mmHg and kept so for at least two years. All patients estimated their glycemia and glycosuria by themselves, ate 0.8 g protein/kg/24 h and about 100 mmol Na/24h. Under hospital conditions the following were estimated: albuminuria, glomerular filtration rate (51Cr EDTA) and effective renal blood flow (131I hippurate). The same examinations were repeated 1 year and 2 years later. The lowering of BP below 100 mmHg in patients with imminent diabetic nephropathy significantly lowered microalbuminuria without changing GFR, ERPF despite good or satisfactory compensation of diabetes. Maintaining BP below 105 mmHg for 2 years did not prevent the patients with overt nephropathy to develop progressive renal failure despite the rate of GFR deterioration and of the increase of albuminuria slowed down.